1. Field of Invention
This invention relates to flame suppressors for gas pipelines.
2. Prior Art
A flame front of an undesired reaction may accidentally start to migrate through a pipeline system. The heat transfer conditions may be such that the flame will be quenches by the large amount of residual cooling of the combination of the environment and the pipeline. However, in other situations the pipeline may be relatively insulated. If the pipe diameter is large so that the total heat content of the flame front is great, then the pipeline may be heated to a temperature causing the rupture of the pipeline.
Inasmuch as ruptures of pipeline attributable to the advancement of a flame front are relatively rare, and inasmuch as the self-dissipation of a flame front can occur under a variety of conditions, there are a variety of engineering considerations tending to decrease the number of flame arrestors scheduled for installation merely to protect the long runs of a pipeline from rupture. However, the hazards inherent in permitting an advancing flame front to enter a gas processing facility, or a chemical plant, or a gas storage facility, are so serious that there is adequate economic justification for flame arrestors protecting substantially all facilities to which pipeline gas might be delivered, notwithstanding the infrequency of such accidents. If a flame front enters either end of a flame arrestor, the cooling effectively quenches the flame before the flame front can advance to the other end of the flame arrestor. Moreover, the flame arrestor is advantageously designed to quench two flame front separated in time by less than an hour or only a few seconds.
Preferred embodiments of the invention of said Ser. No. 860,791 feature a deep pool of heat transfer liquid, in the bottom half of which an array of heat transfer tubes serve to cool the divided gas stream flowing therethrough. Even if the one or more flame fronts involve significant heat, the cooling capacity of the liquid is sufficient to quench each flame front advancing into the reaction boundary suppressor system of said Ser. No. 860,791.
Initial plans contemplated the installation of a flame arrestor as a part of the length of gas line, as indicated in the drawings in said Ser. No. 860,791. Investigations relating to the cost of the construction of flame arrestors, adequacy of foundations, convenience of retrofitting modifications into established gas line systems, have established some disadvantages to the placement of a flame arrestor as an on-line insert into the length of the gas line.